1. Technical Field
The present invention relates to a dehumidification apparatus for reducing the humidity in a closed housing for a hard disk etc. and, more particularly, to a microminiature dehumidification apparatus suited for installation on a cover of a hard disk drive (hereinafter referred to as an HDD), and a dehumidification control system.
2. Description of the Related Art
As a method for keeping the humidity in a hard disk drive low, a conventional method has been used in which a desiccant is arranged in the hard disk drive. Thus, an improved and modern dehumidification system, including means to control the dehumidifying process, would be desirable.
Since a desiccant loses its hygroscopic property after it has absorbed a predetermined amount of water, it cannot keep the humidity in the HDD low for a long period of time. Further, water absorbed once by the desiccant is released again in the HDD for a long time, so that corrosion of the device in the HDD cannot be prevented from occurring from a long-term viewpoint.
An object of the present invention is to provide a microminiature, simply-constructed dehumidifier for removing water in a highly airtight device such as an HDD, a humidifier system in which an air circulation mechanism is added to the humidifier, and a dehumidification control system for keeping the interior of the device at a predetermined humidity or lower by controlling the dehumidifier and the dehumidification apparatus.
The dehumidifier in accordance with the present invention comprises a capillary member which is disposed penetrating a wall for forming two separated spaces so that a first portion thereof is located in one space and a second portion thereof is located in the other space, and the first portion and second portion are connected to each other, by which water can be moved between the two spaces by capillary action or phenomenon; and a heating portion for heating the first portion.
In this case, there may be provided a cooling portion for cooling the second portion of the capillary member.
Further, the construction may be such that the heating portion and cooling portion are heated and cooled, respectively, by the Peltier effect.
The dehumidification apparatus in accordance with the present invention comprises a first air circulator comprising a circulation pipe forming a circulation passage for air; and a pair of air feeders each of which is arranged at both ends of the circulation pipe so that air is fed in the same direction of the circulation passage and an air hole is closed at the time of non-operation; and
a dehumidifier comprising a heating portion formed in the circulation pipe; and a capillary member which is disposed penetrating a wall of the circulation pipe so that a first portion thereof is located inside the circulation pipe and a second portion thereof is located outside the circulation pipe while being connected to the first portion, by which water can be moved between the inside and the outside of the circulation pipe by the capillary phenomenon; the first portion of the capillary member located on the inside being heated by the heating portion.
In this case, a cooling portion may be formed outside the circulation pipe so that the second portion of the capillary member is cooled by the cooling portion.
The dehumidification apparatus of another construction comprises first and second air circulators each comprising a circulation pipe forming a circulation passage for air; and a pair of air feeders each of which is arranged at both ends of the circulation pipe so that air is fed in the same direction of the circulation passage and an air hole is closed at the time of non-operation; and
a dehumidifier comprising a heating portion formed in the first circulation pipe; and a capillary member in which a first portion and a second portion thereof are located so as to be connected to the inside of the first and second circulation pipes, respectively, by which water can be moved between the inside portions of both of the circulation pipes by capillary action or phenomenon; the first portion of the capillary member located inside the first circulation pipe being heated by the heating portion.
In this case, a cooling portion may be formed inside the second circulation pipe so that the second portion of the capillary member is cooled by the cooling portion.
The disk drive in accordance with the present invention comprises a housing formed with a pair of air holes; and the aforementioned dehumidification apparatus, and is constructed so that, of the pair of air feeders of the first air circulator, an air inflow port of the air feeder through which air flows into the circulation passage and an air outflow port of the air feeder through which air flows out of the circulation passage are spatially connected directly to each of the pair of air holes.
The disk drive of another construction comprises a housing formed with a pair of air holes; and the dehumidification apparatus having a pair of air feeders, and is constructed so that an air outflow port of the air feeder through which air flows out of the circulation passage, of the pair of air feeders of the first air circulator, and an air inflow port of the air feeder through which air flows into the circulation passage, of the pair of air feeders of the second air circulator, are spatially connected directly to each of the pair of air holes.
The dehumidification control system in accordance with the present invention has, in addition to the aforementioned disk drive, a humidity sensor disposed in the housing and a controller for controlling the dehumidification apparatus so that the dehumidification apparatus is operated when the humidity in the housing has a value not lower than a predetermined value.
The dehumidification control system of another construction has, in addition to the aforementioned disk drive, a pair of temperature sensors disposed inside and outside the housing and a controller for controlling the dehumidification apparatus so that the dehumidification apparatus is operated based on the temperatures inside and outside the housing.